Influence of gingival color on the color differences of dental laminate veneers.

ABSTRACT

STATEMENT OF PROBLEM: The effect of various gingival colors on the color differences of laminate veneers is unclear and comparative evaluations should be documented. PURPOSE: The purpose of this in vitro study was to investigate the influence of different gingival colors on the color differences of laminate veneers. MATERIAL AND METHODS: Five maxillary typodonts were used to obtain study models using 5 different gingival colors light pink (LP), dark pink (DP), orange (Or), brown (Br), and violet (V). A total of 45 laminate veneers were milled using A1-shaded lithium disilicate ceramic and cemented on natural tooth-colored substrates. Color parameters were assessed using a spectroradiometer at 3 measurement areas (cervical third, mid-third, and incisal third) along the midline of laminate veneer with a focus measuring diameter of 1 mm. Color differences (∆E*ab and ∆E00) were calculated and compared with perceptibility (PT ∆E*ab=1.22, ΔE00=0.81) and acceptability (AT ∆E*ab=2.66, ΔE00=1.77) visual thresholds. Color variation data were statistically analyzed using 2-way ANOVA and Tukey HSD tests (α=.05). RESULTS: Two-way ANOVA results of the ∆E*ab values revealed significant interaction between the gingival color and the measurement area (P=.002). The ∆E*ab and ΔE00 values of laminate veneers were significantly higher in the LP-V group that presented values above AT (P<.001). Measurement area significantly influenced ∆E values of laminate veneers (P<.001). Greater ∆E values were registered at the measurement area of the cervical third in the groups of LP-DP, LP-Br, LP-V, and Or-V. Regardless of the measurement area, ∆E00 values below AT were obtained for the gingival color groups of LP-Or, DP-Or, DP-Br, and DP-V. CONCLUSIONS: Gingival color influenced the color differences of laminate veneers. When the gingival color was a darker gingival color, rather than light pink, the color difference increased, especially at the measurement area of the cervical third.